1. Field of the Invention
Aspects of the present invention relate generally to handset apparatus for use in communication systems, and more particularly to a multi-mode wireless handheld apparatus incorporating a radio component operative in accordance with a plurality of communication standards.
2. Description of Related Art
Recently, the Worldwide Interoperability for Microwave Access (or “WiMAX”) communication standard, as promoted by the Institute of Electrical and Electronics Engineers (IEEE) and defined by the IEEE 802.16 specification, has emerged as a potential replacement or overlay for traditional cellular wireless service. As is known in the art, the IEEE 802.11 standard (generally known as Wireless Fidelity, or “WiFi”) may support Voice over Internet Protocol (VoIP) for handheld apparatus and other wireless devices. It is expected that future consumer and industry demand will require that wireless devices be capable of operating in more than one mode, e.g., WiFi and WiMAX or WiFi and cellular. Conventional implementations generally require multiple transceivers, each of which is operative to support a specific communication standard. Interaction between multiple radio elements in a single device, however, can create interference and other deleterious effects that limit the utility of the device, its useful range, or booth; inter-radio interference is especially problematic where individual receivers, transmitters, or both are manufactured independently (e.g., on different chips) and perhaps by different manufacturers. Additionally, current technology generally does not permit implementation of a WiFi transceiver in WiMAX mode, for example, and vice-versa. While these communication standards, or modes, are similar, sufficient differences exist to limit the ability of one transceiver which is dedicated to operate in one particular mode (e.g., WiFi) from operating in the other mode (e.g., WiMAX).
Similarities between the WiFi and WiMAX standards generally include basebands and overall bandwidth requirements, media access control (MAC) elements, channel size and spacing, as well as hardware components and protocol stacks which support various operational characteristics; for example, both modes represent multi-in, multi-out (MIMO) technologies. Despite the similarities between WiFi and WiMAX implementations, conventional devices that have been constructed to operate in both modes have nevertheless not taken advantage of these similarities, and continue to rely upon multiple transceivers which typically interfere. Further, while it may be desirable in some situations to allow an apparatus to share resources such as memory between a WiFi transceiver and a WiMAX transceiver, conventional implementations have failed to do so efficiently.
Hence, it may be desirable to provide a multi-mode wireless handheld apparatus incorporating a multi-mode wireless radio that can operate in accordance with various communication standards interchangeably.